فیلترها/جستجو در نتایج    

فیلترها

سال

بانک‌ها




گروه تخصصی











متن کامل


نویسندگان: 

AFSHAR KAZEMI MOHAMMAD ALI | DARVISH MOTEVALLI MOHAMMAD HOSSEIN | DARVISH MOTEVALLI MAHMOOD

اطلاعات دوره: 
  • سال: 

    2016
  • دوره: 

    1
  • شماره: 

    3
  • صفحات: 

    39-54
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    348
  • دانلود: 

    0
چکیده: 

Today, information Networks play an important role in supply chain management. Therefore, in this article, clustering-based routing protocols, which are one of the most important ways to reduce energy consumption in wireless sensor Networks, are used to optimize the supply chain informational cloud Network. Accordingly, first, a clustering protocol is presented using self-organizing map neural Network, SOM. Second, we cluster the Network nodes based on two criteria of neighborhood and energy level using K-means clustering pattern. Third, we survey the efficiency and inefficiency of the clusters to balance the energy properly among the clusters. Then, to increase the Network Lifetime and to maintain the Network DEA method is used. Finally, the model is tested for the information Network of oil supply chain.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 348

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
اطلاعات دوره: 
  • سال: 

    2017
  • دوره: 

    5
  • شماره: 

    4
  • صفحات: 

    225-235
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    399
  • دانلود: 

    0
چکیده: 

The tiny and low-cost sensors cannot simultaneously sense more than one channel since they do not have high-speed Analog-to-Digital-Convertors (ADCs) and high-power batteries. It is a critical problem when they are used for multi-channel sensing in cognitive sensor Networks (CSNs). One solution for this problem is that the sensors sense various channels at different sensing periods. Due to the energy limitation in these scenarios, the Lifetime maximization will become an important issue. In this paper, maximizing the Lifetime of a CSN is investigated by selecting both the cooperative sensors and their detector threshold, such that the desired detection performance constraints are satisfied. This is a NP-complete problem, and obtaining the optimum solution needs exhaustive search with exponential complexity order. Here we have proposed two convex-based optimization algorithms with low order of complexity. First algorithm applies the known instantaneous Signal-to-Noise-Ratio (SNR) and obtains the proper detector thresholds by solving an equation for every channel. Investigation the effect of detector thresholds on the energy consumption, the false alarm probability and the detection probability shows that we can minimize the detector thresholds such that the detection constraints are met. In the second algorithm in order to reduce the needed time for obtaining answers, the Bisection method is proposed for determining detector thresholds. Because knowing the instantaneous SNR is difficult, we have investigated the performance of the second algorithm by average value of SNR. Simulation results show that the proposed algorithms improve the performance of the Network in case of Lifetime and energy consumption.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 399

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
اطلاعات دوره: 
  • سال: 

    1394
  • دوره: 

    7
  • شماره: 

    23-24
  • صفحات: 

    25-35
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    996
  • دانلود: 

    420
چکیده: 

پیشرفت های اخیر در زمینه الکترونیک و مخابرات بی سیم، توانایی طراحی و ساخت حسگرهایی را با توان مصرفی پایین، اندازه کوچک، قیمت مناسب و کاربری های گوناگون داده است. ظرفیت محدود انرژی حسگرها، چالش بزرگی است که این شبکه ها را تحت تاثیر قرار می دهد. خوشه بندی به عنوان یکی از روش های شناخته شده برای مدیریت این چالش استفاده می شو. برای یافتن مکان مناسب سرخوشه ها از الگوریتم رقابت استعماری که یکی از شاخه های هوش محاسباتی می باشد استفاده شده است. سرخوشه ها توسط مدل سه سطحی در ارتباط هستند، تا سرخوشه هایی با ظرفیت انرژی کم و دور از ایستگاه به عنوان سطح سوم شناخته شده و به طور غیر مستقیم با ایستگاه پایه به تبادل اطلاعات بپردازد. این موضوع باعث افزایش طول عمر شبکه های حسگر بی سیم می شود.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 996

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 420 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
نویسندگان: 

Haghzad Klidbary S. | Javadian M.

اطلاعات دوره: 
  • سال: 

    2024
  • دوره: 

    37
  • شماره: 

    9
  • صفحات: 

    1800-1811
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    27
  • دانلود: 

    0
چکیده: 

Wireless sensor Networks contain of many sensors that can serve as powerful tools for data collection in environments. A key challenge in these Networks is the limited Lifetime of sensor batteries. Ideally, all nodes would exhaust their energy simultaneously or through regular scheduling, maximizing the Lifetime. Consequently, the primary concern is achieving optimal energy utilization to extend the Network's Lifetime over a logical duration. Depleting the batteries of the sensors means stopping the operation of the Network, because it is practically impossible to replace the batteries of thousands of nodes. To address this issue, the low energy adaptive clustering hierarchical (LEACH) protocol has been widely recognized as one of the prominent solutions for clustering WSNs. However, the random selection of cluster heads in each round under the LEACH protocol fails to guarantee proper convergence. To overcome this limitation, this paper proposes a refined approach by utilizing a genetic algorithm and a novel objective function that incorporates various factors, including energy level and distance. The algorithm employs chromosomes to represent CHs and facilitates the selection of cluster nodes. Notably, the proposed algorithm dynamically performs clustering, meaning that clustering is conducted iteratively, considering identifying dead nodes. By leveraging this approach, the algorithm significantly enhances the clustering quality, ultimately leading to an increased Network Lifetime. To validate its effectiveness, it is compared with LEACH, LEACH_E and LEACH_EX algorithms, demonstrating its superior capabilities. On average, the proposed algorithm has more alive nodes in the Network, and the remaining energy is at least 11% higher than the best other algorithms.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 27

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
همکاران: 

اطلاعات : 
  • تاریخ پایان: 

    1395
تعامل: 
  • بازدید: 

    236
کلیدواژه: 
چکیده: 

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 236

نویسندگان: 

RAJA P. | DANANJAYAN P.

اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    10
  • شماره: 

    1
  • صفحات: 

    10-17
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    385
  • دانلود: 

    0
چکیده: 

Abstract: Wireless Sensor Networks (WSNs) comprising of tiny, power-constrained nodes are getting very popular due to their potential uses in wide applications like monitoring of environmental conditions, various military and civilian applications. The critical issue in the node is energy consumption since it is operated using battery, therefore its Lifetime should be maximized for effective utilization in various applications. In this paper, a Game theory based Hybrid MAC protocol (GH-MAC) is proposed to reduce the energy consumption of the nodes. GH-MAC is combined with the game based energy efficient TDMA (G-ETDMA) for intra-cluster communication between the cluster members to head nodes and Game theory based nanoMAC (G-nanoMAC) protocol used for inter-cluster communication between head nodes. Performance of GH-MAC protocol is evaluated in terms of energy consumption, delay and compared with conventional MAC schemes. The results obtained using GH-MAC protocol shows that the energy consumption is enormously reduced and thereby the Lifetime of the sensor Network is enhanced.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 385

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
نویسنده: 

Alaee Aghil | Goli Sareh

اطلاعات دوره: 
  • سال: 

    2017
  • دوره: 

    13
تعامل: 
  • بازدید: 

    228
  • دانلود: 

    0
چکیده: 

THE CONCEPT OF "RESIDUAL Lifetime" IS A USEFUL TOOL TO STUDY THE RELIABILITY ENGINEERING. IN THE PRESENT ARTICLE, WE CONSIDER A SYSTEM WITH WEIBULL DISTRIBUTION AND TRUNCATED WEIBULL DISTRIBUTION Lifetime AND ASSUME THAT THE SYSTEM IS WORKING AT TIME T. UNDER THESE CONDITIONS, THE MEAN RESIDUAL Lifetime OF THE K-OUT-OF-N SYSTEM IS OBTAINED UNDER DIFFERENT SCENARIOS ON THE SYSTEM. SEVERAL PROPERTIES OF THE MEAN RESIDUAL Lifetime ARE DERIVED. IN ADDITION, THE DISCUSSED CONCEPTS ARE EXPLAINED BY WORKING OUT REAL NUMERICAL EXAMPLE ABOUT AIRPLANE TIRES.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 228

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0
اطلاعات دوره: 
  • سال: 

    1394
  • دوره: 

    13
  • شماره: 

    1
  • صفحات: 

    77-82
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    1304
  • دانلود: 

    268
چکیده: 

شبکه مش بی سیم، شبکه ای چندجهشه متشکل از مسیریاب ها و کاربران مش می باشد که امکان یک پارچه کردن شبکه های بی سیم موجود، جهت ارائه سرویس با ویژگی های متنوع تر و بهتر را فراهم می آورد. مسیریاب ها به صورت خودکار به برقراری ارتباط بی سیم بین یکدیگر می پردازند، بنابراین در بسیاری موارد نیاز به اعمال مدیریت و صرف هزینه هنگفت برای راه اندازی شبکه وجود ندارد. از طرفی این گونه از شبکه ها دارای قابلیت متصل کردن شبکه های ناهمگون به هم هستند و می توانند از استانداردهای متنوعی پشتیبانی کنند. در مواردی که مسیریاب های زیرساخت شبکه مش به انرژی برق شهری دسترسی نداشته باشند، استفاده از شبکه مش بی سیمی که با باتری و انرژی خورشیدی کار می کند، بسیار مفید خواهد بود. در این حالت اساسی ترین مشکل، اتمام سریع شارژ باتری ها و قطع شبکه است و لذا در این مقاله راهکاری برای افزایش طول عمر شبکه و استفاده بهینه از انرژی باتری گره ها پیشنهاد شده که می تواند مدت زمان کارکرد شبکه را بسیار بالا ببرد. الگوریتم مسیریابی پیشنهادی، گره هایی در شبکه را با بیشترین انرژی باقیمانده مشخص کرده و داده ها فقط از میان گره های تعیین شده عبور می کنند تا زمانی که انرژی یک گره به سطح آستانه از پیش مشخص شده نزدیک شود. نتایج شبیه سازی نشان می دهد که این روش کارایی بهتری نسبت به شیوه های متداول مسیریابی و ارسال اطلاعات در این نوع شبکه ها دارد.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 1304

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 268 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    12
  • شماره: 

    2-4 (B)
  • صفحات: 

    47-58
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    271
  • دانلود: 

    0
چکیده: 

The area of wireless sensor Network is shrouded with significant ranges of problems where majority of the prior research attempts were carried out to address energy conservation issues. The present manuscript introduces a novel technique called as ENLPL or Enhancing Network Lifetime Using Probabilistic Logic where the prime focus is laid on conserving the energy for large scale wireless sensor Network. ENLPL presents design of inter and intra clustering approach using probability theory. It also laid emphasis on ensuring maximum participation of the sensor nodes in selection process of cluster-leader with an aid of maximum number of parameters. The outcome of the study was compared with conventional and standard hierarchical clustering algorithm (LEACH) to find ENLPL ensures better energy efficiency for large number of the sensor. With the adoption of the probabilistic reasoning technique, the simulation results shows that the proposed system maximizes the cumulative Lifetime of the Network, along with an efficient selection process of the cluster leader in every iteration.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 271

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
اطلاعات دوره: 
  • سال: 

    2020
  • دوره: 

    14
  • شماره: 

    3
  • صفحات: 

    11-22
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    131
  • دانلود: 

    0
چکیده: 

Todays, Wireless Body Sensor Networks (WBSNs) are used as a useful way in health monitoring. One of the most important problems regarding Wireless Body Sensor Network (WBSNs) is Network Lifetime. This factor mainly relies on the energy consumption of sensors. In fact, during capturing vital sign data and also communicating them to the coordinator, the biosensors consume energy. In this article, we are interested to propose an energy efficient Adaptive Sampling (AS) rate specification algorithm to set the amount of sensed data. According to the National Early Warning Score (NEWS), the sensors gather data and detect emergency data. Two scenarios have been used; the first is utilizing context recognition to indicate the active and sleep sensors in different time slices and the second is using watchdog sensors for checking patient situation in critical condition. Simulation results show that the proposed method can save energy and increase Network Lifetime by up to 4 times more than the previous work. In addition, our methods allow on average 75% improvement in overhead data reduction while maintaining more than 90% data integrity.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 131

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
litScript
telegram sharing button
whatsapp sharing button
linkedin sharing button
twitter sharing button
email sharing button
email sharing button
email sharing button
sharethis sharing button